The old adage, "records are made to be broken," certainly applies to plants. Each year gardeners from throughout the world compete with their
largest tomatoes and squash, largest potatoes and turnips, largest orchids,
tallest sunflowers and dozens of other superlative categories. Authenticated
records of their prized fruits, vegetables and blossoms appear in the latest
editions of the Guinness Book Of World Records. But of all the botanical records, the most remarkable come from wild plants growing in their natural
habitats. These "contestants" compete in a vast natural arena known as the
world ecosystem or biosphere. Although most of these astonishing plants are
listed in the Guinness Book, several have never been rightfully acknowledged.

1. The World's Oldest Living Thing

Up until the late 1970's, the oldest living thing was thought to be a tree called the bristlecone pine (Pinus longaeva), living for nearly 5,000 years high in the White Mountains of California and the Snake Range of eastern Nevada. Then, Dr. Frank Vasek of the University of California at Riverside investigated the strange, circular growth patterns of a flowering shrub called creosote bush (Larrea tridentata) in the Mojave Desert. Dr. Vasek proved that each giant ring of shrubs came from its own ancestral shrub that once grew from the
center of the ring. The interesting circular growth pattern can be explained
by examining sections of creosote bush stumps (stem crowns) at the base of
the shrubs.

Under the tree category there may be a rival to the bristlecone pine. The following information comes from a recent issue of Yahoo News (Friday 11 April 2008). Prossesor Leif Kullman of Umea University in Sweden reports a Norway spruce (Picea abies) high in the mountains separating Norway and Sweden that is 8,000 years old. The age determination was based on carbon dating at a laboratory in Miami, Florida. Two other windswept spruces were shown to be 4,800 and 5,500 years old. There may be some disagreement among dendrochronologists as to whether carbon dating is as accurate as the ring-counting method used on the ancient bristlecone pines. At any rate, the creosote bush rings appear to be at least 2,000 years older.

Fragmented creosote bush stem crown.

The original stem crown splits and fragments into sections. As the segments continue to grow outwardly (away from the center) they produce new branches along their outer edge. This is like an expanding tree trunk with the center wood dying and rotting away, with only the outer (peripheral) tissue remaining alive and producing branches.

Over thousands of years the center wood dies and rots away, leaving a barren area surrounded by a circular ring of shrubs. One of the oldest shrub rings is 50 feet (15 m) in diameter. It has been
estimated that it started from a seed 11,700 years ago. During its
lifetime the last major period of glaciation in North America (Wisconsin
Glaciation) came to an end, the great Egyptian and Mayan pyramids were built,
the first human walked on the moon, routine satellites and manned spaceships
orbited the earth...and the shrub is still living.

Since the creosote bush stump (crown) splits vegetatively into genetically identical fragments, these sections could technically be referred to as clones; however, the clone scenario opens up a whole new category for the world's oldest living thing. For example, forests of quaking aspen (Populus tremuloides) in North America cover hundreds of acres. In one dense stand covering more than 100 acres, researchers discovered that all the trees were essentially genetically identical and shared a common root system. This massive clonal colony has spread across meadows and mountain slopes for many centuries. Another massive and very ancient plant clone in North America is the huckleberry (Gaylussacia brachycera), a member of the heath family (Ericaceae). According to the Tasmania Parks and Wildlife Service (1997), a rare and endangered shrub of the protea family (Proteaceae) called King's Holly (Lomatia tasmanica) may be the oldest plant clone in the world. The plants appear to be sterile triploids incapable of producing viable seeds. The clonal thickets reproduce vegetatively by root suckering and have been estimated to be at least 43,000 years old. Fossil leaves found in a late Pleistocene deposit may be genetically identical to present-day plants. Another ancient tree from southern Tasmania is the huon pine (Lagarostrobos franklinii), a member of the Podocarpaceae. Some individuals growing in deep canyons are thought to be at least 2,000 years old. These are not clonal populations, they are the actual trees that lived during the time of Christ.

Ancient Antarctic Beech: Lophozonia (Nothofagus) moorei

Clonal populations of this tree with multiple trunks have reportedly been alive for 2500-3000 years. An article in Smithsonian by Rachel Sussman describes huge trees in Lamington National Park, Queesland, Australia that are 12,000 years old. They are considered by some authors to be relicts of the great southern subcontinent Gondwanaland, when South America and Africa were connected with each other and with Antarctica, India, and Australia. This is roughly the time when the first flowering plants began to appear on earth. I have not found any scientific references to verify these ages for Lophozonia moorei.

Antarctic Beech: Lophozonia (Nothofagus) moorei in Lamington National Park, Queesland, Australia. Photo from Wikimedia Commons, but photographer is not given.

Many crustose rock lichens spend most of their lives in a desiccated state and have extremely slow annual growth rates. On massive domes and
rugged peaks of the Sierra Nevada, large colonies of the lime-green map
lichen (Rhizocarpon geographicum), ashy gray Aspicilia cinerea, and orange Caloplaca saxicola may be thousands of years old. In fact, the colorful chartreuse rock lichen Acarospora chlorophana may only grow a few millimeters in a century. One has only to gaze at the spectacular panoramas of glacier-carved granite throughout the Sierra Nevada to appreciate the magnitude of growth and the great age of some of these lichen colonies. Because they grow at a constant rate, map lichens in Glacier National Park have been estimated to be 8,600 years old.

Left: Spectacular granite domes of Yosemite National Park in California's rugged Sierra Nevada are blackened by colonies of the crustose rock lichen Lecidea atrobrunnea. Close-up view of a hand lens and Lecidea atrobrunnea, a common crustose lichen throughout granite peaks and domes of the Sierra Nevada. The photo was taken at the summit Polly Dome, the highest dome in Yosemite National Park.

Left: A granite boulder covered with colonies of map lichen (Rhizocarpon geographicum). This species of crustose lichen is appropriately named because the colonies resemble continents on the earth.

Middle & Right: Some desert boulders rocks are coated with desert varnish, a reddish layer of clay and iron oxide (or manganese oxide) precipitated by remarkable bacteria that live on the rock surface. The thin layer of reddish iron oxide varnish on this rock surface has been etched to reveal the lighter granodiorite beneath. In some deserts of the world it takes 10,000 years for boulders to be completely coated with desert varnsish.

Any discussion of ancient life would be incomplete without mentioning a remarkable discovery made in a deep mine shaft near Carlsbad, New Mexico. Bacterial spores of the genus Bacillus were isolated from pockets (inclusions) in salt crystals harvested from an underground salt bed 2,000 feet (610 m) below the surface. The salt deposits were formed from an ancient sea in a geologic formation that dates back about 250 million years. What is so remarkable about these spores is that microbiologists succeeded in growing them in a laboratory. The spores have survived in a cryptobiotic state millions of years before dinosaurs roamed the earth. Another microbe extracted directly from dissolved salt crystals appears to be related to the archaebacteria that thrive in the brine of present-day salt lakes. NASA is interested in ancient salt deposits because the planet Mars and Jupiter's moon Europa once had oceans and may have similar subterranean salt formations. Space missions in search of extraterrestrial life may eventually explore these ancient salt beds. For more about this significant discovery, see the article by R.H. Vreeland, W.D. Rosenzweig and D.W. Powers (2000), "Isolation Of A 250 Million-Year-Old Bacterium From A Primary Salt Crystal," Nature 407: 897-900.

The World's Oldest Germinated Seed

There are several documented records for the oldest viable seeds. The most recent record (June 2005) is the seed of a date palm (Phoenix dactylifera) that was discovered during an archaeological excavation at King Herod's Palace on Mount Masada near the Dead Sea. Nicknamed "Methuselah" the palm that sprouted from this ancient seed has been Carbon-dated at about 2,000 years old. Since date palms are dioecious, it is not known whether the palm is male or female. Another seed viability record is the Asian water lotus (Nelumbo nucifera) in which a seed from China was successfully germinated after 1,200 years. But the world's record is the seed of an Arctic lupine (Lupinus arcticus) that was excavated from a lemming burrow in frozen Arctic tundra. The seed germinated and flowered after an estimated 10,000 years of dormancy. The latter record was not mentioned in the MSNBC Online Technology & Science article about a 2,000-year-old date palm seed.

In 2012, a team of scientists from The Institute of Cell Biophysics of the Russian Academy of Scientists successfully regenerated seeds of Silene stenophylla (Caryophyllaceae) from fruit that had been frozen for 30,000 years according to radiocarbon dating. The fruits and seeds were recovered from an acient rodent burrow in Siberian permafrost. This white-flowered Silene is the oldest plant ever to be grown from a seed: S. Yashina, S. Gubin, S. Maksimovich, et al. (2012) "Regeneration of Whole Fertile Plants From 30,000-y-old Fruit Tissue Buried in Siberian Permafrost." Proceedings of the National Academy of Sciences USA doi: 10.1073/pnas. 11183861. Silene stenophylla is an extant species that grows in the tundra of far eastern Siberia. It has incised petals that are white or lilac in color. There are almost 100 taxa (species and subspecies) of Silene in North America, including 36 in California.

Silene verecunda ssp. platyota, a white-flowered species that grows in the mountains of southern California. The flowers in above photo have a full-blown case of anther smut (Ustilago violacea), a sexually transmitted disease that affects the anthers. This debilitating fungal disease causes the male organs (anthers) to blacken and shrivel, resulting in sterility and a very unsightly floral appearance. The brown, sooty, fungal spores are spread by insects to other flowers.

2. The Oldest Living Fossil On Earth

One of the oldest living fossils--or plant genera that lived during ancient times and still lives on earth today is the remarkable maidenhair tree (Ginkgo). Leaf imprints of an ancestral species of Ginkgo resembling the present-day Ginkgo biloba have been found abundantly in sedimentary rocks of the Jurassic Period of the Mesozoic Era (140-200 million years ago) when dinosaurs
roamed the earth. According to K. Bauer, et al. (2013), Ginkgo seedling fossils resembling present-day Ginkgo biloba also extend into the mid-Triassic Period more than 200 million years ago. All North American plantings of this splendid tree are
living descendants of trees only known from the orient, cultivated by people
in temple gardens for countless generations. Petrified logs
of this tree have been uncovered from their ancient tomb of flood sediments
and lava flows near the Columbia River Gorge of central Washington. They
once formed great forests in this region 150,000 centuries ago. The fan-shaped leaves are similar in shape to the individual leaflets of the lovely maidenhair fern (Adiantum). Interestingly enough, the veins of Ginkgo leaves are dichotomously branched (forked into 2 branches), a very primitive vascular plant characteristic. This distinctive type of venation was also present in the leaves of many extinct members of the order Ginkgoales known only from the fossil record.

Characteristic fan-shaped leaves of a living Ginkgo biloba. It belongs to the botanical division (phylum) Ginkgophyta, a true gymnosperm with "naked" seeds. This is not a flowering plant, and the cherry-like "fruit" is not a fruit at all. It is a naked seed that is not enclosed in a ripened ovary or fruit, unlike all true flowering plants (angiosperms).

The ripened ovary (fruit) is composed of one or more carpels (modified leaves). It is easy to see that the single carpel of a milkweed (Asclepias) fruit (called a follicle) is a modified, seed-bearing leaf (megasporophyll).

A modern representation of the phylogeny of gymnosperms based on chloroplast DNA. Dichotomous (paired) sister branches (clades) with a common ancestor are said to be monophyletic and are more closely related. For example, the conifer division Pinophyta (Coniferophyta) and ginkgo division (Ginkgophyta) have a common ancestor in the cycad division (Cycadophyta). The pine family (Pinaceae) and a sister branch leading to six additional families have a common ancestor within the division Pinophyta. In other words, the seven major families of cone-bearing trees and shrubs all evolved from the division Pinophyta. The araucaria and podocarpus families (Araucariaceae and Podocarpaceae), which have their greatest diversity in the southern hemisphere, are monophyletic and occur side-by-side on sister clades. Chart by E.M. Armstrong (2008).

I recently received an e-mail message from Brian Ottway of Portugal regarding the fern Osmunda claytoniana. According to an article in the American Journal of Botany (1998), Osmunda fronds from Triassic deposits in Antarctica are virtually identical to modern O. claytoniana. The fossil fern has been named O. claytoniites and dates back 200-250 million years ago. Modern Osmunda claytoniana is native to the eastern United States, Canada and eastern Asia. Fossil evidence indicates that this species had a circumboreal distribution across North America, Europe and Asia.

3. The World's Most Massive Living Thing

Prior to the discovery of ancient bristlecone pines and creosote bush rings, the world's record for longevity went to the magnificent giant sequoia (Sequoiadendron giganteum) of the western slopes of the Sierra Nevada. The greatest authenticated age of a giant sequoia, derived from counting annual rings on a cut stump, was nearly 3,200 years. Although it may fall short of the world's oldest, a giant sequoia in Sequoia National Park has the undisputed record for the
world's most massive living thing. The largest tree, named General Sherman,
is 272 feet (83 m) tall with a massive trunk 35 feet (11 m) in diameter and 109 feet (33 m) in
circumference at the base. Even more remarkable is the fact that at a point
120 feet (36 m) in the air the trunk of General Sherman is still 17 feet (5 m) in
diameter. It has been estimated to contain over 600,000 board feet of
timber, enough to build 120 average-sized houses. In fact, a single giant
sequoia may contain more wood than is found on several acres of some of the
finest virgin timberland in the Pacific Northwest. The trunk of General
Sherman alone weighs nearly 1400 tons. By way of comparison, this is roughly
equivalent to 15 adult blue whales, 10 diesel-electric train locomotives, or
25 average-sized military battle tanks.

Sequoiadendron giganteum in King's Canyon National Park.

Another conifer species called the Montezuma bald cypress (Taxodium mucronatum) occasionally grows into a huge tree. One enormous specimen of this tree grows in the churchyard of Santa Maria de Tule near Oaxaca, Mexico. Called "El Gigante" by the locals, it is one of the most massive of all living things with a trunk circumference of 140 feet (43 m), larger than the General
Sherman giant sequoia. With a diameter of 50 feet (15 m), the trunk of this
spectacular tree is literally the size of a house. This gigantic tree was
once thought to be 10,000 years old, but botanists now consider it to be a
youngster of only 1,500 to 2,000 years.

Some flowering trees such as the African baobab (Adansonia digitata featured in the movie "The Gods Must Be Crazy--Part II"), the South American ombu (Phytolacca dioica) and the Indian banyan (Ficus benghalensis) also have enormous trunks up to 100 feet (30 m) or more in circumference, but do not grow as tall. One large baobab trunk can store 25,000 gallons of water weighing 100 tons. According to E. Palmer and N. Pitman (Trees of South Africa, 1961), a tree with a volume of 7,500 cubic feet may contain 30,000 gallons of water. This amount of water alone would weigh an astonishing 120 tons. The Indian banyan also has the record for the world's largest (spreading) tree crown, with 1000 pillar-like prop roots supporting massive limbs that cover four acres. Alexander the Great reportedly camped with an army of 7,000 soldiers under such a fig tree. Other trees of the tropical
rain forest, such as the kapok tree (Ceiba pentandra) of Central and South America, also develop huge buttressed trunks.

A South African baobab tree (Adansonia digitata), one of the most massive flowering plants. The enormous trunk may exceed 100 feet (30 m) in circumference and store 25,000 gallons of water weighing 100 tons. [Photo by Paul Armstrong]

Left: A large Indian banyan (Ficus benghalensis) at the Gauguin Botanical Garden in Tahiti, French Polynesia. The trunks in foreground are large aerial prop roots from the enormous tree in the distance. Right: A massive strangler fig (Ficus cotinifolia) in Yucatan with numerous vinelike, aerial roots growing from the limbs. Some of the roots have fused (anastomosed) into massive pillars. The decayed trunk of the host tree is still visible inside the strangler's web of fused aerial roots.

Based on measurements of height, canopy spread and trunk diameter, a Moreton Bay fig (Ficus macrophylla) in Glendora, California is the largest cultivated tree in California with a point score of 700. Enormous Moreton Bay figs in Santa Barbara and Balboa Park (San Diego) are the 2nd and 3rd largest. For comparison, the General Sherman giant sequoia of Sequoia National Park has a total point score of 1800!

This is how large a Moreton Bay fig (Ficus macrophylla) can get in just over one century in southern California! It was planted in Glendora, California in the late 1800s. The enormous surface roots cover 1200 square feet (40 square meters). In its native habitat of eastern Australia, this species becomes a gigantic strangler.

The mycelium of some forest fungi can extend
enormous distances. A single individual
of Armillaria bulbosa has been discovered that permeates more than 30 acres of forest soil in northern Michigan. Some scientists speculate that it was spawned by a single
spore thousands of years ago. Another species of Armillaria (A. ostoyae) in the Blue Mountains of eastern Oregon was recently found to consist of a subterranean mycelial network with erect, above-ground
mushrooms covering more than 2,000 acres of forest soil. The largest colonies of Armillaria have been estimated to be 1500 to 2400 years old. See recent article by Dr. Ramesh Maheshwari of the India Institute of Science in Bangalore: "The Largest and Oldest Living Organism," Resonance April 2005: 4-9.

Mushroom fruiting bodies of the forest fungus Armillaria mellea

Armillaria mellea includes a variable complex of mushrooms that are often found growing in massive clusters at the base of trees in the forest. The mycelium of some Armillaria species may extend through the soil for hundreds of acres.

These fungal
monstrosities are rivaled in total size and mass by a 106 acre, 6,000 ton
stand of genetically identical quaking aspen (Populus tremuloides) in the Wasatch Mountains of Utah. The aspen clone is connected (in part) by a common root system, and
has literally climbed over mountains and across meadows. The age of this giant clone has been estimated at 10,000 years or more. Any discussion of
massive clonal colonies should also include the conjoined polyps of coral
reefs. However, the question still remains: Do these clonal colonies qualify
as a single individual, as in the 1400 ton General Sherman?

An aspen clone in the Wasatch Mountains of Utah is composed of 47,000 stems of genetically identical aspen trees (Populus tremuloides), with a total weight of 6 million kilograms (6,500 tons). Since the aspen is a dioecious species (with separate male and female individuals in the population), this monstrous clone is the same sex, in this case all males. The clone has developed asexually by suckering, where new adventitious stems arise from a gigantic spreading root system. Suckering is a common method of asexual reproduction in the willow family (Salicaceae), which includes cottonwoods (Populus), willows (Salix) and aspen. The above-ground stems appear to be separate trees, but they all arose from a genetically identical root system. Like the creosote bush clones in the White Mountains of California, it is quite likely that some of the root systems have broken away, so that some of the trees are no longer directly connected to the clone, but they still share a common genome.

Aspen trees (Populus tremuloides) commonly reproduce asexually by suckering (adventitious stems). In some regions of western North America, entire forest populations (stands) may be genetically identical. For thousands of years these enormous clonal populations have been spreading across meadows and mountain slopes, and many of the trees actually share a common root system.

4. The World's Tallest Tree

The world's record for the tallest tree goes to another cone-bearing tree native to California, the coast redwood (Sequoia sempervirens). In fact, the tallest living redwood on record stands 379 feet (116 m), 64 feet (20 m) taller than the Statue of Liberty. The California redwoods are rivaled in size by the amazing flowering Australian mountain ash (Eucalyptus regnans). The record for the tallest tree of all time has been debated by botanists for more than a century. Some amazing claims for towering Douglas fir (Pseudotsuga menziesii) and E. regnans exceeding 400 feet (122 m) have never been substantiated by a qualified surveyor. In 1872, a fallen E. regnans 18 feet (5.5 m) in diameter and 436 feet (133 m) tall was reported by William Ferguson near Watts River, Victoria. The tree had fallen after a brush fire and was measured by Ferguson with a tape. There is some controversy over the exact length, but if correct this would certainly be the tallest (or perhaps longest) fallen tree on record. According to the International Society of Aboriculture, Australian Chapter, a record-breaking E. regnans at Thorpdale, Victoria was reportedly 374 feet (114 m) tall. It was measured with a theodolite (cf. transit) in the 1880s. Unfortunately, this remarkable tree was cut down. It was almost six feet (2 m) taller than the current tallest living redwood. According to the monograph on Eucalyptus by Stan Kelly (Volume 1 of Eucalypts, 1977), trees of E. regnans well over 300 feet (91 m) tall have been measured, but the tallest tree known to be standing at present is 322 feet (98 m).

5. The World's Hardest & Heaviest Wood

Most of the other remarkable plant records go to the flowering plants. This is not surprising since flowering plants have colonized practically
every conceivable habitat on earth, from vast submarine meadows in oceans and
bays to arid deserts and windswept alpine summits. At least a dozen species
of flowering trees called "ironwoods" hold the title of world's heaviest
wood. Wood is composed of dead cells of a tree trunk, particularly the inner
xylem tissue when the bark is removed. The weight of wood is essentially due
to the cellulose and lignin in the cell walls of billions of cells.
Ironwoods all have wood with very dense, heavily lignified cells with little
or no air spaces in the cell cavities (lumens). The pure cell wall material
has a specific gravity of about 1.5, and the heaviest and hardest ironwoods
approach 1.4. Since pure water has a specific gravity of 1.0, ironwoods with
specific gravities greater than 1.0 will sink in water. Certainly one of the
world's heaviest and hardest ironwoods is the Caribbean tree called lignum
vitae (Guaiacum officinale), with a specific gravity of 1.37. The name
lignum vitae means "wood of life," owing to the medicinal properties of the
sweet-smelling resin. The density and high resin content of the wood make it
extremely resistant to friction and abrasion and account for its remarkable
self-lubrication properties. Under certain conditions it actually wears
better than iron. In fact, the highly-prized wood was used for end grain
thrust blocks which lined the propeller shafts of steamships. [Note: The
Guinness Book of World Records lists the South African black ironwood (Olea laurifolia) as the heaviest wood with a specific gravity of 1.49. This is rather doubtful since the specific gravity of pure cell wall material is 1.5 (i.e. without any cellular structure), and samples of Olea laurifolia I have tested only weighed in at about 1.11.] By way of contrast, cork bark from the European cork oak (Quercus suber) has a specific gravity of 0.24; and the tropical American balsawood tree (Ochroma pyramidale) is one of the world's softest and lightest woods with a specific gravity of only 0.19.

6. The World's Smallest Flowering Plant

There are approximately 230,000 species of described flowering plants in the world, and they range in size from diminutive alpine daisies only a few inches tall to massive eucalyptus trees in Australia over 300 feet (91 m) tall. But the undisputed world's smallest flowering plants belong to the genus Wolffia, minute rootless plants that float at the surface of quiet streams and ponds.

Each plant is shaped like a microscopic green football with a flat top. An average individual plant of the Asian species W. globosa, or the equally minute Australian species W. angusta, is small enough to pass through the eye of an ordinary sewing needle, and 5,000 plants could easily fit into thimble. It is difficult to say which is the smaller of the two, but perhaps W. globosa may be slightly smaller. An average individual plant is 0.6 mm long (1/42 of an inch) and 0.3 mm wide (1/85th of an inch). It weighs about 150 micrograms (1/190,000 of an ounce), or the approximate weight of 2-3 grains of table salt. One plant is 165,000 times shorter than the tallest Australian eucalyptus (Eucalyptus regnans) and seven trillion times lighter than the most massive giant sequoia (Sequoiadendron giganteum). Another mind-boggling comparison is the size or volume of a single wolffia plant: roughly intermediate between a water molecule and the planet earth.

If a water molecule is represented by 100, then a wolffia plant is about 1020 power larger than the water molecule. The earth is about 1020 power larger than a wolffia plant, or 1040 power larger than the water molecule.

Wolffia plants also produce the world's smallest flower, a bouquet of one dozen plants will
easily fit on the head of a pin and two Wolffia angusta plants in full bloom will fit inside
a small printed letter "o" on this page.

Several individuals of Wolffia angusta placed lengthwise inside the "eye" of an ordinary sewing needle. The distinctive dorsal margin is clearly visible on one of the plants. The width of one plant body is the same as a single strand of sewing thread, making this one of the smallest species of wolffia. It is rivaled in size only by the Asian species W. globosa and the African species W. cylindracea. If the Wolffia illustrations in the following table are proportional in size, then the Australian W. angusta would appear to be the world's smallest flowering plant.

A recent article by J. Travis in Science News Vol. 155 (April 17, 1999) discusses a remarkable new species of sulfur bacteria from the greenish ooze of ocean sediment off the coast of Namibia in southwestern Africa. Sulfur bacteria oxidize sulfur compounds to produce their energy-rich ATP molecules. The spherical bacteria have diameters ranging from 0.1 to 0.75 mm, definitely within the size range of some species of Wolffia. The bacteria were discovered in sediment samples by Heide Schulz of the Max Planck Institute for Marine Microbiology in Bremen, Germany (see the April 16, 1999 issue of Science). The new species is named Thiomargarita namibiensis, or sulfur pearl of Namibia. When light shines on the bacterial cells, they glisten white from light reflecting off sulfur inside them (see the image above). Because of their size and light-reflecting properties, the bacteria are visible to the naked eye, roughly the size of a printed period or the size of an average grain of table salt (NaCl). But who would ever believe that a multicellular flowering plant could be as small as one prokaryotic bacterial cell. This is certainly the case with Wolffia globosa, especially if you consider the size of a single daughter plant that has broken away from the parent plant by budding (see the images above). And although it is the ultimate in reduction of a flowering plant, it actually has minute guard cells and stomata on its upper (dorsal) surface. Any way you look at these amazing records; a giant bacterial cell or a microscopic flowering plant, they are truly wonders of the world. A single sperm cell from Zamia roezlii, an interesting cycad endemic to rain forests of Colombia, is about 0.4 mm in length and is visible to the unaided eye. In fact, it is almost as large as one entire wolffia plant. It consists of several spiral bands of 20,000 to 40,000 cilia at one end. The pulsating beat of these cilia may help to propel the sperm through the pollen tube on its journey to fertilize the egg.

Each wolffia plant produces a microscopic flower (consisting of one stamen and one pistil) inside a small cavity on the upper side of the plant body. Tiny wolffia plants are commonly dispersed on the feet of water fowl, tucked neatly under the duck's bodies during flight. In the southeastern United States there are records of wolffia plants being carried by a tornado, and they have been reported in the water of melted
hailstones. By way of comparison, the world's largest flower is produced by
a parasitic plant (Rafflesia arnoldiii) native to the Malay Archipelago. This bizarre plant lives inside climbing vines of the tropical rain forest. Like
a gigantic erupting pimple, a rafflesia flower bud breaks through the bark of
the host vine and expands into an enormous foul-smelling blossom up to three
feet (0.9 m) in diameter and weighing up to 20 pounds. In fact, it is sometimes
called the "stinking corpse lily."

Candy sprinkles compared with a thimble filled with wolffia plants (mostly Wolffia columbiana). The average diameter of a globose wolffia plant body is about 1/25th of an inch (1 mm). To appreciate their minute size, wolffia plants are comparable in size to the multicolored candy sprinkles used for decorating cakes and cookies.

Left: Dorsal view of several budding Wolffia borealis in full bloom. The floral cavity on the dorsal side reveals a circular concave stigma (nearest the basal end) and a single, pollen-bearing anther. Unlike Lemna, Spirodela and Landoltia, the flower is not enclosed within a membranous spathe. The flowers are protogynous, with the stigma becoming receptive before the anther matures and sheds pollen. The far right plant shows only the stigma, while the far left plant shows only the anther. The top and bottom plants show both the stigma and a faint anther. As of 21 January 2010, no wolffia plants have been reported from Anza Borrego Desert. Right: Lateral view of flowering Wolffia borealis showing the dorsal floral cavity containing one anther-bearing stamen and one pistil (gynoecium). The pistil has a seed-bearing ovary, a slender (short) style and a circular, concave stigma. The flowers are protogynous, with the stigma becoming receptive before the anther matures and sheds pollen. A daughter plant protrudes from a funnel-like budding pouch at the basal end. The entire flowering plant is only one millimeter (1/25th of an inch) in length. It weighs approximately 200 micrograms (roughly 1/150,000 of an ounce).

A budding Wolffia borealis in full bloom. The floral cavity on the parent plant contains a minute pistil (gynoecium) with a circular concave stigma and a single stamen with a minute pollen-bearing anther. The plant is compared with the tip of an ordinary sewing needle and a cubical grain of ordinary table salt (NaCl). Three grains placed side-by-side are approximately 1 mm in length.

What Is The Largest Flowering Plant?

According to the Guinness Book of World Records, "The Largest Blossoming Plant" is an enormous Chinese wisteria vine (Wisteria sinensis) growing at a private residence in the quaint city of Sierra Madre in southern California. The Japanese wisteria (W. floribunda) is very similar genetically and the two species hybridize. Both species are invasive vines (lianas) that are naturalized in the southeastern United States. Since flowering plants (angiosperms) produce blossoms, this record could also be stated: "The World's Largest Flowering Plant." The vine was planted in 1894 from a one gallon pot. It covers nearly an acre and weighs over 250 tons. During a five week blooming period it produced over 1.5 million blossoms. It is one of the Guinness Book of World Records "Seven Horticultural Wonders of the World":

For a showy, cultivated flowering vine, the famous Sierra Madre wisteria is certainly one of the largest; however, in technical botanical terms there are flowering trees that rival or exceed this vine in massiveness. The Australian mountain ash (Eucalyptus regnans) can exceed 300 feet in height. In fact, some of the tallest trees rival the California coast redwood (Sequoia sempervirens) in height. As I stated above, the South African baobab tree (Adansonia digitata) is a massive flowering plant. The enormous trunk may exceed 100 feet (30 m) in circumference with a volume of 7,500 cubic feet. It reportedly can store 25,000 gallons of water weighing 100 tons. The Indian banyan (Ficus benghalensis) has the record for the world's largest (spreading) tree crown, with 1000 pillar-like prop roots supporting massive limbs that cover four acres. Figs (Ficus) produce thousands of ovoid, "fruit-shaped" structures called syconia, each containing hundreds of minute, apetalous, unisexual flowers. An aspen clone in the Wasatch Mountains of Utah is composed of 47,000 stems of genetically identical aspen trees (Populus tremuloides), with a total weight of 6 million kilograms (6,500 tons). It is connected (in part) by a common root system, and has literally spread across 106 acres of forests and meadows. It started out as one individual male plant thousands of years ago and has developed asexually by suckering, where new adventitious stems arise from a gigantic spreading root system. The flowers of some of these record-breaking tree species have inconspicuous, unisexual, apetalous flowers that could hardly be recognized as blossoms; however, they are nonetheless true flowering plants. Most people associate the word "blossom" with conspicuous, showy flowers, so the record "Largest Blossoming Plant" is probably horticulturally fitting for the spectacular Sierra Madre wisteria, even though it is not entirely botanically accurate.

This giant Indian banyan (Ficus benghalensis) on the island of Maui covers about one acre. It undoubtedly exceeds the Sierra Madre wisteria in total weight, but its flowers can hardly be called "blossoms" to garden enthusiasts.

A dense stand of quaking aspen (Populus tremuloides). Some aspen stands share a common root system and are genetically identical clones covering many acres. They started out as a single plant many centuries ago. Collectively, they represent an enormous flowering plant weighing hundreds of tons.

Banyan figs are enormous flowering plants, but their flowers are minute. Tiny male & female flowers inside a fig syconium are only a few millimeters long. They have no petals and consist of a single pistil or several stamens. Male & female flowers of aspen are produced in catkins and consist of a single pistil or a cluster stamens. Although they technically qualify as true flowers, they are not showy blossoms.

A related family of parasitic flowering plants (the Rafflesiaceae) contains the "stinking corpse lily" (Rafflesia arnoldii), the world's largest individual flower and truly a wonder of the plant kingdom. It has been called the "giant panda of the plant world" because this rare and endangered species only occurs in the rain forests of Sumatra and Borneo in the Malay Archipelago. Unlike most flowering plants, it has no leaves or
stems and grows endoparasitically within the woody stems of its host vine
Tetrastigma, a relative of the grape. Unless you saw evidence of an old blossom, you could walk right past a Tetrastigma vine without ever knowing that a complete Rafflesia plant lives inside its stem. Occasionally a large flower bud resembling a pale orange cabbage breaks through the bark of the host vine and expands into an enormous blossom up to 3 feet (0.9 m) in diameter and weighing up to 25 pounds (11 kg). The gigantic unisexual flower has five fleshy red lobes (sepals) spattered with raised white spots. With an odor reminiscent of a stinking corpse, the blossom attracts carrion beetles and flies which shuttle the pollen from male to female flowers. A single female flower may produce up to four million seeds which are dispersed by a
variety of animals, from ants, tree shrews and squirrels, to the feet of
wild pigs and Asian elephants. If a seed becomes lodged in a moist crevice
on its host vine, it germinates and penetrates the host tissue where it
proliferates into a network of microscopic filaments of cells. These
fungus-like networks of vascular tissue eventually give rise to a mammoth
blossom that pushes out through the host stem, making Rafflesia one of the most intriguing and unusual plants on earth. The chances of a seed finding a host vine are slim, and massive deforestation has further decreased the
odds of this remarkable event. Recently the governments of Indonesia and
Malaysia have begun to recognize the marketable curiosity value of this
plant and ecological preserves are being established.

The infamous "stinking corpse lily" (Rafflesia arnoldii), the world's largest flower. This remarkable Malaysian/Indonesian endoparasite lives completely within its host vine, and occasionally breaks through the bark as a huge bud that expands into an enormous blossom up to 3 feet (0.9 meter) in diameter.

The Bolivian bromeliad, Puya raimondii produces one of the largest flower clusters or inflorescences. The individual flower stalk may be over 30 feet (9 m) tall, bearing more than 8,000 white blossoms. This enormous flower stalk is rivaled by some species of Agave. According to Charles E. Hubbuch, Director of Plant Collections at the Fairchild Tropical Garden in Coral Gables, Florida, the talipot palm (Corypha umbraculifera) of India has the largest inflorescence of any plant. The huge inflorescence may be 10 meters (over 30 feet) tall with millions of flowers.

Chaparral yucca (Yucca whipplei), a native member of the agave family thast grows wild in the coastal sage scrub adjacent to the Palomar College Arboretum. Flower close-up shows two black yucca moths (Tegeticula maculata) which are the natural pollinator for this interesting yucca species in San Diego County.

Agave americana

The inflorescence in left image is about 30 ft. tall. This species is monocarpic: It flowers and bears fruit only once and then dies. Century plants (Agave) and some yuccas (Yucca whipplei) bloom after 8-10 to 20 years or more and then die. Most of the Agave's resources go into the enormous, rapid-growing flower stalk. At the base of the withering leaves, small "pups" will take the place of the dying mother plant. Most varieties of bamboos in cultivation are clones derived from a single plant that may be traced back to one seed. This may explain why some cultivated bamboos have the same flowering cycle and mortality as populations on different continents. By far the majority of bamboo species are not monocarpic, i.e. they do not flower gregariously and then die.

The most remarkable carrion arum is the titan arum or bunga bangkai "corpse flower" (Amorphophallus titanum). Native to equatorial tropical rain forests of Sumatra, Indonesia, this amazing plant flowered at the New York Botanical Garden in 1937. At its maximum development, a spadix over 8 feet tall (2.4 m) emerged from a huge vase-shaped, pleated spathe over 4 feet (1.2 m) tall and 12 feet (4 m) in circumference. This floral giant developed from a tuber measuring 6 feet (2 m) in circumference and weighing over 100 pounds (46 kg). According to B. Meeuse and S. Morris (The Sex Life Of Flowers, 1984), the enormous blossom generates such an overwhelming smell that people have been known to pass out from taking too close a whiff.

Right: The magnificent titan arum (Amorphophallus titanum) at the Huntington Botanic Garden on August 3, 1999 (one day after its peak blooming period). The large, funnel-shaped spathe (red on the inner surface) is already folded closed in photo. Thousands of people witnessed this very unusual blossom. Those lucky enough to be at Huntington Botanic Garden on the previous day (August 2) saw this spectacular inflorescence with the reddish spathe opened wide, resembling the drawing on the commemorative T-shirt (right), for sale at HBG. To find out more about this amazing plant (or T-shirt) log on to the Huntington Botanic Garden web site at www.huntington.org.

In some carrion flowers the insects are lured into dark openings leading to the putrefying interior where they become trapped among the
floral organs. This strategy insures cross pollination, especially when
the male anthers release pollen several days after the female stigma is no
longer receptive. When the imprisoned insects are allowed to leave they
are given a thorough dusting of fresh pollen to be taken to a different
plant. One of the classic insect-trapping carrion flowers is the European Dutchman's pipe (Aristolochia clematitis), a member of the birthwort family (Aristolochiaceae). The unusual common names are derived from the curious blossoms with a shape reminiscent of Sherlock Holmes' pipe, and an old herbal remedy. Some species in this family have aromatic roots that were reputedly used as a purgative to induce labor, a questionable practice that is not recommended. The curious blossoms of some species superficially resemble a human fetus in the womb, and the plants were once thought to facilitate child birth. During medieval times, various ailments were treated with plants that resembled certain afflicted parts of the body. This practice was called the "Doctrine of Signatures," and became the basis of medical treatment for centuries to come. The striking, tubular flower of Dutchman's pipe is held upright as it emits a foul, pungent odor. Small gnats land on the vertical upper calyx surface but slip down through the floral tube and into the inflated "pipe chamber" due to slippery wax granules on the inner surface. Dense, downward-pointing hairs in the floral tube prevent the gnats from climbing out. During their incarceration the gnats receive rations of nectar. Several days later,
when the anthers release pollen, the jail hairs wilt and the flower tilts
horizontally, allowing the pollen-laden gnats to walk out of their prison,
and into another receptive floral trap on a different plant.

A Dutchman's pipe (Aristolochia californica) native to the Coast Ranges of Central and Northern California, and foothills of the Sierra Nevada. This California species is pollinated by fungus gnats.

The bizarre flower of a Brazilian Dutchman's pipe Aristolochia gigantea. The front view (left) shows a central yellow spot where an opening leads into an enclosed pouch. The back view (right) superficially resembles a pair of lungs with a canal leading into an inflated, stomach-like pouch. The blossom is over 14 inches (36 cm) long.

7. The World's Smallest & Largest Fruit

Wolffia also produces the world's smallest fruit, although this record is not as yet recognized in the Guinness Book. Each one-seeded fruit is about the size of a cuboidal grain of ordinary table salt (0.3 mm long) and weighs about 70 micrograms (1/400,000 of an ounce). It is roughly five
billion times lighter than a 900 pound
squash.

Fruits of the duckweed family (Lemnaceae). The small, bladderlike, thin-walled fruit is technically called a utricle. Because of their small size (usually only 1-2 mm or less), fruits of the duckweed family are seldom seen. In fact, the one-seeded fruits of Wolffia species are the undisputed smallest fruits on earth. Two of the smallest are the Australian W. angusta (shown in photo) and the Asian W. globosa. The wolffia fruits were photographed in an alcohol (ethanol) solution and the salt grains have dissolved slightly resulting in rounded corners and the appearance of ice cubes; however, they are truly grains of table salt measuring only 0.3 mm on a side.

The world's smallest fruits are produced by species of Wolffia, including the Australian W. angusta. The above image shows a mature fruit within the plant body. The larger fruit of Lemna shows a thin, transparent pericarp surrounding a ribbed seed. A pericarp layer is not evident on the wolffia fruits.

Although duckweeds of the genus Lemna have plant bodies a little larger than wolffia, the one-seeded fruits of some species are almost as small. The photo at left shows a minute fruit protruding from a budding pouch at the top of a tropical duckweed (L. aequinoctialis). The head of an ordinary straight pin is shown as a size relationship.

According to Cucurbits, the official newsletter of the World Pumpkin
Confederation, a 1993 record-breaking pumpkin weighed in at 836 pounds and a
giant squash tipped the scales at just over 700 pounds. One year later at
the "gourd olympics" in Port Elgin, Ontario, the reign of the pumpkin was
broken by a 900 pound squash. There have been other unofficial records for
pumpkins exceeding 900 pounds. To enter your prize pumpkin in the official
World Pumpkin Confederation Annual Weigh-Off, it must be cream-yellow to
orange; if it is green to gray or mottled in color it must be entered as a
squash. Many pumpkins are varieties of Cucurbita pepo, although the largest pumpkins probably come from C. maxima.

NOTE: When this article was first uploaded and placed on-line in the spring of 1996, it appeared that the squash had clearly beaten its long-time rival, the pumpkin, and was indeed the world's largest fruit (at least according to contests sponsored by the World Pumpkin Confederation). But finally, on that fateful day of October 5, 1996 at the official World Pumpkin Confederation weigh-in at Clarence, New York, the pumpkin once again regained its title of the world's largest fruit. Not only did a record-breaking pumpkin beat its 900 pound squash rival of 1994, but it also broke the 1,000 pound barrier where no pumpkin or squash had ever gone before. For their remarkable 1,061 pound mammoth pumpkin, the lucky growers received a grand prize of 50,000 dollars. In another pumpkin contest held at Canfield, Ohio in October 2000, a pumpkin weighed in at 1140 pounds. In October 2002, a pumpkin was reported from Manchester, New Hampshire with an astonishing weight of 1337 pounds. At the October 1, 2005 Giant Pumpkin Growers Weighoff in Pennsylvania, a pumpkin weighing 1469 pounds was reported. In October 2010 at Stillwater Harvest Fest, Stillwater, Minnesota, a giant pumpkin weighed in at 1,810.5 pounds.

The jackfruit (Artocarpus heterophyllus) produces massive seed-bearing fruits on its branches. Native to the Indo-Malaysian region, this tree is grown throughout the tropics for its pulpy, edible fruit. It belongs to the same genus as the famous breadfruit (A. altilis). According to Charles Heiser (Seed to Civilization, 1973), jackfruits may reach nearly three feet (0.9 m) and weigh up to 75 pounds (34 kg), thus making them the largest tree-bearing fruits on earth. Of course, the undisputed record for the world's largest fruit is a 1337 pound pumpkin, a member of the gourd family (Cucurbitaceae).

The World's Largest Bean Pod & Seed Cones

Left: The world's largest been pods come from woody vines or lianas of the genus (Entada). They are native to the rain forests of the Old and New World tropics. The largest species is called the sea heart (E. gigas), and the pods may be 5 feet (1.5 m) long. The woody, heart-shaped seeds of Entada gigas are carried by torrential rains into rivers and eventually into the sea where they often drift to the shores of distant continents and islands. Right: Although technically not a fruit, California's coulter pine (Pinus coulteri) has one of the largest seed cones on earth. Of all the more than 100 species of pines in the world, this is one of the most massive cones. They may be up to 14 inches (36 cm) long and weigh more than 8 pounds (3.6 kg). Other pines, such as the sugar pine (P. lambertiana) have longer cones, but they have flimsy cone scales and do not weigh as much. The heavy cones of Coulter pine with talon-like, curved scales are definitely a hazard to anyone standing or sleeping under a cone-laden limb. Seed cones of the Australian bunya-bunya tree typically weigh 10 pounds (4.5 kg) or more, and definitely pose a danger to mortal humans if you stand under a large tree during "cone-dropping" season. The undisputed world's largest seed cones are produced by tropical cycads of the genera Lepidozamia and Encephalartos. The largest cones are three feet (0.9 m) long and weigh up to 95 pounds (45 kg).

The world's largest legume fruits (bean pods) are produced by the tropical liana Entada. The longest pods of the Central American E. gigas may be up to 5 feet long (1.5 m). This gigantic woody vine is truly like Jack's fabulous bean stalk. In Costa Rica it is called "monkey ladder" or "escalera de mono." The woody seeds of E. gigas are called "sea hearts" and are often washed down streams to the sea where they drift across the ocean to distant continents. Familiar edible legume pods in the background include green beans, peanuts, soybeans and snow peas.

The World's Largest Sperm

Cycads also have the record for the world's largest sperm. A single sperm cell from Zamia roezlii, an interesting cycad endemic to rain forests of Colombia, is about 0.4 mm in length and is visible to the unaided eye. It is roughly the size of an average grain of table salt or a dust mite. In fact, it is almost as large as one entire wolffia plant! It consists of several spiral bands of 20,000 to 40,000 cilia at one end. The pulsating beat of these cilia may help to propel the sperm through the pollen tube on its journey to fertilize the egg.

8. The World's Largest Hitchhiking Fruit

Seed-bearing fruits that cling to the bodies of animals are very effective methods of seed dispersal in the plant kingdom. There are literally hundreds of plant species with hitchhiking seed pods, but some of the largest are from the North American devil's claw (Proboscidea). The devil's claw fruit is technically a drupaceous
capsule with a woody inner part surrounded by a fleshy layer. The rather
sinister common name of "devil's claw" refers to the inner woody capsule which splits open at one end into two curved horns or claws. Each
capsule contains about 40 black seeds which are gradually released when
the claws split apart. They are also called "elephant tusks" and readily cling to the hooves of grazing animals or your shoes if you happen to
step on them. In some areas of the southwestern United States they are a nuisance to sheep ranchers because they get entangled in the fleece. In his
fascinating book, Plants and Planet (1974), Anthony Huxley (son of
Julian Huxley) eloquently describes the hitchhiking pods as "hookers." The fresh green pods (and dried black seed capsules) were important items
in the cultures of many Indian tribes of the southwestern United States, and are still used to this day for food and in basketry. The striking seed pods of the domesticated, white-seeded cultivar P. parviflora ssp. parviflora var. hohokamiana have
claws up to 15 inches (38 cm) long. Multiclawed forms have also
also selected by native Americans because the horns split into 3-4 claws. The long claws are soaked in water and split into leathery strands. They provide durability and intricate black designs in tightly woven baskets made from sun-bleached yucca leaves (often Yucca elata). The devil's claw is also known as "unicorn plant" referring to the large, hornlike fruit before is has split
open.

The seed capsules of devil's claws are clearly adapted for hitchhiking on the hooves of large grazing animals; however, with the exception of introduced livestock and people (and possibly desert bighorn sheep), there are few native North American animals living within the present range of devil's claws that are capable of dispersing these large hitchhikers. It is possible that the range of some large North American grazers, such as antelope, bison, deer and elk once overlapped the range of devil's claws thousands of years ago. It is also possible that devil's claw dispersal by grazing mammals may be a North and South American anachronism, or an occurrence that is out of its proper time in history. During the past one million years of the Pleistocene Epoch, the Americas were rich in large mammals (such as giant ground sloths) which are now extinct. Assuming devil's claw plants existed over 600,000 years ago, were some of these ancient mammals the true carriers of these hitchhiker pods? A similar anachronism occurs in the New World tropics of Central and South America, where the natural dispersal agent for some large seed pods are unknown.

9. The World's Largest Vegetable

If you define a botanical vegetable as an edible part of a plant that clearly excludes seed-bearing fruits, then there are a number of possible contenders for this coveted record. [Note: We are not using the Webster's definition which states that a vegetable is an edible plant part typically eaten with your main entree, but not as a dessert.] Remember that pumpkins and squash must be disqualified because they are seed-bearing fruits even though they may be eaten with your main entree. Some of the top contenders for this record are the blades of large brown algae called kelp, and the tender leaves of the horseradish tree (Moringa oleifera), not to be confused with the true horseradish of the mustard family (Armoracia lapathifolia). Perhaps a more logical contender for this record are the massive subterranean yams of the genus Dioscorea, some of which may weigh over 120 pounds (54 kg). In order to reduce the size of this file and the time it takes to load, the "World's Largest Vegetable" section is placed on another file under the September 1996 Issue Of Noteworthy Plants:

10. The World's Smallest & Largest Seed

Certain epiphytic orchids of the tropical rain forest produce the world's smallest seeds, up to 35 million per ounce. One seed weighs about one 35 millionths of an ounce (1/35,000,000) or 0.81 micrograms. Some seeds are only about 1/300th of an inch long (85 micrometers). [The resolving power for an unaided human eye with 20-20 vision is just under 0.1 mm.] Orchid seeds are dispersed into the air like minute dust particles or single-celled spores,
eventually coming to rest in the upper canopy of rain forest trees. The
world's largest seed comes from the coco-de-mer palm (Lodoicea maldivica), native to the Seychelles Archipelago in the Indian Ocean. Although it belongs to a different genus from true coconut palms (Cocos), this enormous seed is often called the "double coconut." A single seed may be 12 inches (30 cm) long, nearly three feet (0.9 m) in circumference and weigh 40 pounds (18 kg). It should be noted here that the largest seed does not have the largest embryo. In fact, palm seeds are mostly composed of endosperm tissue and generally have relatively small embryos (see photo link below).

Small seeds. Mustard family (Brassicaceae): Black mustard (Brassica nigra). Orchid family (Orchidaceae): Coral-root orchid (Corallorhiza maculata). Duckweed family (Lemnaceae): Watermeal (Wolffia angusta), a one-seeded fruit called a utricle. Poppy family (Papaveraceae): Opium poppy (Papaver somniferum). Without any doubt, the orchids have the record for smallest seeds. The seeds of some species are no larger than fungal spores and occur in a loose cellular sheath. Since the seeds have no endosperm and underdeveloped embryos, there are practically no food reserves. In order to germinate under natural conditions, they must establish a symbiotic relationship with a compatible mycorrhizal fungus. During early stages of development, the fungus supplies critical nutrients to the orchid seedling. Later the orchid may become fully independent, or it may retain its mycorrizal relationship throughout its life. The above coral-root orchid seed (Corallorhiza) grows into a nonphotosynthetic mycotrophic wildflower. It absorbs carbohydrates and minerals from its fungal host, which in turn absorbs these vital nutrients from the roots of nearby forest trees. Orchid seeds are also grown under aseptic conditions in nutrient agar, similar to bacterial and fungal cultures. Wolffia certainly has the record for smallest fruits which are not much larger than grains of ordinary table salt (NaCl). The single seed inside is almost as large as the fruit; therefore, wolffia seeds are not as small as orchid seeds.

Microscopic view of the seed of a coral-root orcid (Corallorhiza maculata). The individual seed is only about 0.2 mm in diameter. In fact, there are unusual bacterial cells that are larger than this orchid seed. The resolving power for an unaided human eye with 20-20 vision is about 0.1 mm. With its cellular sheath (seed coat) removed, this seed is barely visible to the naked eye. Certain epiphytic orchids of the tropical rain forest produce the world's smallest seeds weighing only 35 millionths of an ounce. One seed capsule from a single flower may contain up to four million seeds. They are dispersed into the air like minute dust particles or single-celled spores, eventually coming to rest in the upper canopy of rain forest trees. The seeds of some species are no larger than fungal spores and occur in a loose cellular sheath. Since the seeds have no endosperm and a minute, undifferentiated embryo, there are practically no food reserves. In order to germinate under natural conditions, they must establish a symbiotic relationship with a compatible mycorrhizal soil fungus. During early stages of development, the fungus supplies critical nutrients to the orchid seedling. Later the orchid may become fully independent, or it may retain its mycorrhizal relationship throughout its life. The above coral-root orchid seed (Corallorhiza) grows into a nonphotosynthetic mycotrophic wildflower that is completely dependent on its mycorrhizal fungus. Throughout its life, the orchid absorbs carbohydrates and minerals from its fungal partner, which in turn absorbs these vital nutrients from the roots of nearby forest trees. In a laboratory, orchid seeds can be grown in nutrient agar, like a sterile (axenic) culture of bacteria or fungal spores.

The seed pod (capsule) of an unknown orchid containing many thousands of minute seeds. Each seed is enclosed in a cellular sheath (seed coat) resembling a short, silky hair. The seeds are dispersed into the wind like dust particles. In nature, the probability of an orchid seed finding a suitable place for germination and a compatible fungal partner are unlikely, so millions of seeds are released to increase the odds.

According to C.R. Gunn (World Guide To Tropical Drift Seeds and Fruits, 1976), the record for the largest seed embryo goes to Mora oleifera (Fabaceae), a large tree that grows in tidal marshlands and estuaries along the Pacific coast of tropical America. In Costa Rica, this tree often forms nearly pure stands just behind the mangrove swamps. Seeds of M. oleifera may be up to 7 inches (18 cm) long and up to 5 inches (8 cm) wide. Another species (M. excelsa) has slightly smaller seeds. Like other exalbuminous legume seeds, the two cotyledons comprise most of the seed. Since the cotyledons are part of the embryo, this species is certainly a strong contender for the record of world's largest seed. The seeds float in ocean current with their two large cotyledons connected or separate. Dried cotyledons washed up on beaches superficially resemble the shells of a bivalve mollusk.

Seed of Mora oleifera showing the two large cotyledons. Since the cotyledons are technically part of the embryo, this is perhaps the largest embryo of any seed. Mora oleifera is a large tree that grows in tidal marshlands along the Pacific coast of tropical America. The seeds float in ocean water with their two large cotyledons connected or separate. Dried cotyledons that wash ashore on beaches superficially resemble the shells of a bivalve mollusk.

Provocative seed and immature fruits of the Seychelles Island Palm (Lodoicea maldivica). Like the coconut (Cocos nucifera), the seed is enclosed by a thick, woody endocarp. The complete fruit (drupe) contains of an enormous, seed-bearing endocarp surrounded by a husk composed of a thin mesocarp and a smooth, outer exocarp. This is truly the largest seed produced by any plant on earth.

11. The World's Largest & Smallest Leaves.

In addition to the largest seeds, palms also have the record for the largest leaves. The raffia palm (Raphia regalis) of tropical Africa has huge pinnate leaves up to 80 feet (24 m) long. The leaves of the Amazonian palm (Manicaria saccifera) are nearly 30 feet (8 m) long, and have been listed by some authors as the longest undivided leaf of any plant. However, according to Chuck Hubbuch of Fairchild Tropical Garden, Coral Gables, Florida, the leaf is typically divided shallowly at the tip and is not truly entire. The golf ball-sized fruits of Manicaria palms, called "sea coconuts," commonly wash ashore on beaches throughout the Caribbean and southern Florida. There are two additional palm candidates for the record of longest undivided leaf: Marojejya darianii, a palm native to Madagascar with a leaf up to 5 meters in length that is divided only once at the tip; and joey palm (Johannesteijsmannia altifrons), a palm native to Thailand with a leaf up to 4 meters long that is completely undivided. In the Private Life of Plants (BBC nature series), David Attenborough says "the giant arum of Borneo develops the biggest undivided leaf of all"--a surface area of 34 square feet. Without accurate dimensions for the Joey palm leaf, it is difficult to calculate its surface area; however, according to Internet images it appears to rival the size of the giant arum. Thanks to Eric Platt for bringing this to my attention.

Circular floating leaves of the giant Amazonian water lily (Victoria amazonica) have a documented diameter of up to 2.4 meters (8 feet). Using the simple formula for the area of a circle (A = πr²), the largest leaves would have an area of 50 square feet. This is 47 percent larger than the leaf reported by David Attenborough.

Giant Amazon water lily (Victoria amazonica), a member of the water lily family (Nyphaeaceae).

The World's Smallest Leaves

If you define a true leaf as a flattened, photosynthetic organ arising from the stem axis in vascular plants, then there are numerous contenders for the world's smallest leaf. Since mosses are nonvascular (without xylem tissue), they would generally be excluded from this record. Ferns are vascular plants, and the common water fern (Azolla filiculoides) has leaves that are only one mm in length. The minute California wildflower called pygmy weed (Crassula erecta) has minute fleshy leaves about 1.3 mm long. This is the diameter of the head of an ordinary straight pin. Many species in the cypress family (Cupressaceae) have overlapping scalelike leaves only 1-2 mm in length. This includes cypress (Cupressus), junipers (Juniperus), and cedars (Chamaecyparis and Thuja). Although the body of duckweeds has paired guard cells and stomata on its upper surface and superficially resembles a leaf (particularly the flattened duckweeds Spirodela, Landoltia and Lemna), it is morphologically and embryonically completely different. I prefer to call it a plant body rather than the term frond or thallus. The duckweed Spirodela polyrrhiza has a membranous, scalelike leaf (prophyllum) that envelops the dorsal and ventral surfaces of the basal end. This basal portion and its connecting stalk correspond to a condensed shoot that has become greatly reduced through evolution. In fact, more advanced members of the duckweed family, including Lemna, Wolffia and Wolffiella have lost this basal prophyllum altogether. In Spirodela polyrrhiza, one or more roots pass through the prophyllum on the underside of the plant body. The prophyllum is also visible on the underside of rootless, overwintering turions. Average turions are approximately 1/25th of an inch (1 mm) in length and 1-2 mm in width. The minute prophyllum is only about 1/75th to 1/50th of an inch (0.3 mm to 0.5 mm) in length. If the prophyllum is considered a greatly reduced leaf, then it is one of the smallest in the plant kingdom.

Close-up view of the water fern (Azolloa filiculoides). The overlapping scalelike leaves (black arrow) are about 1/25th of an inch (1 mm) in length. Also shown in the photo are three species in the duckweed family (Lemnaceae): Wolffia borealis (1), W. columbiana (2) and Lemna minuta (3). Although the latter three species are very small, they do not have leaves.

Close-up view of a branchlet from the Oriental arborvitae (Thuja orientalis = Platycadus orientalis). Many species in the cypress family (Cupressaceae) have overlapping scalelike leaves only 1-2 mm in length. The white dots are stomata, minute pores each flanked by a pair of guard cells. Gas exchange with the atmosphere is accomplished through the stomata.

Left: Pygmy weed (Crassula erecta), a member of the stonecrop family (Crassulaceae). The minute leaf is about 1.3 mm long (the diameter of the head of an ordinary straight pin). Right: Turion of the duckweed Spirodela polyrrhiza, a member of the duckweed family (Lemnaceae). The turion is about 1.2 mm in width and 1.0 mm long. Note the minute, transparent, bractlike leaf called a prophyllum at the basal end. The prophyllum is only about 1/50th of an inch (0.5 mm) in width and 1/75th of an inch (0.3 mm) long. It overlaps both the dorsal and ventral sides of the turion, but is more visible on the lower (ventral) surface. The prophyllum of Landoltia punctata is much smaller and is truly microscopic. If the prophyllum is homologous to a leaf in its embryonic origin, then it is certainly should be recognized as one of the world's smallest leaves.